Press



Oct. 6, 1936. w. KLOCKE 2,

PRESS Filed Oct. 25, 1935 2 Sheets-Shet 1 Oct. 6, 1936. w. KLOCKE2,056,402

' PRESS Filed Oct. 25, 1955 2 Sheets-Sheet 2 INVENTOR.

W/LLIAMKL cKE ATTORNEY.

Patented Oct. 6, 1936 UNITED STATES ATENT OFFICE 9 Claims.

This invention relates to presses, and provides improvements therein.

The present invention achieves an advance in the accuracy with whichmetal parts may be formed by a press operation, the invention providinga press by which metal can be bent and drawn to an accuracy within a fewten-thousandths of an inch of a required dimension. The mechanism issuch that the slide may have a substantial and normal strokecharacteristic of presses for general purposes, and have a dwell of anabsolute nature at the bottom-of-thestroke position while the slideactuating parts are moving through a considerable part of their cycle ofmovement.

The invention further provides a press of the character described whichis of simple construction, and in which driving forces are transmittedto the moving parts at good working angles, and with good mechanicaladvantage, and in which the working stresses are advantageouslydistributed in the frame of the press. It further provides a press inWhichthe shocks and strains on the press-tools are greatly eased, whileallowing 25 of the application of great forces and pressures to thematerial operated on by thepress.

The invention further provides a press having a clutch of the positiveengagement type in which the clutch parts can be disengaged andre-engaged while the press-slide is in its bottom-ofthe-stroke positionand the frame under maximum stress, against a relatively very smallresistance, and in which, furthermore, the driving mechanism may turnthrough a greater or less angular distance of considerable amount afterengagement of the clutch parts, against said relatively small resistanceso that the driving mechanism can gain or retain considerable momentumbefore meeting the relatively great resistance required to free thepress-tools and lift the pressslide from its bottom-of-the-strokeposition.

An embodiment of the invention is illustrated in the accompanyingdrawings, wherein:

Fig. l is a view thereof in side elevation, with parts broken away tobetter illustrate certain of the working parts.

Fig. 2 is a view, from the underside, of the levers and connectionsshown in side elevation in Fig. 1.

Fig. 3 is a diagrammatic view illustrating the slide actuating mechanismin the positions which the parts occupy in the bottom-of-the-strokeposition of the slide.

Fig. 4 is a diagrammatic view illustrating the engaging and disengagingaction of a clutch of the well known oscillating-key type.

Figs. 5, 6 and 7 illustrate a suitable clutch having the mode ofoperation illustrated and described with reierence to Figs. 3 and 4;Fig. 5 5 7 being a longitudinal sectional view, and Figs.

6 and 7 being sections each on the line VIIVII Fig. 5, Fig. 6 showingthe parts at the beginning of the clutch engagementiand Fig. '7 showingthe parts at the start of the operation to engage 10 the clutch.

Referring to said drawings, numeral I0 designates the press-frame,between the sides of which is a slide l2 arranged to be reciprocated insuitable gibs on the frame by the actuating l5 mechanism about to bedescribed. The slide actuating mechanism comprises the knuckle-jointedlevers l4, l5, turning on the bearings ll, ii! on the frame and on theslide respectively, a pair of toggle levers 20, 2|, pivotally connected,as indicated by 22, a crank (or an equivalent, such as an eccentric) 24,and a connecting or pitmen-rod connecting the crank 24 with theconnected toggle levers 20, 2|.

The crank 24 is turned by any suitable means, 25 as by a pinion on theshaft 3| of a fly-wheel pulley 33, meshing with a large gear wheel onthe shaft 37 of crank 24.

The connected toggle-levers 2|], 2| are connected at one end to a fixedbearing 40 on the 30 press frame It and at the opposite end to theknuckle-jointed levers |4, |5, and the arrangement and correlation issuch that when the crank 24 is turning in its dead-center arc (about 90of movement) the toggle-levers 20, 2| are ap- 5 proximately in line (thecenter 22 moving through a small arc of the order of 10 across the lineof dead-center alinement of said levers 20, 2|) and the knuckle-jointedlevers |4, |5 remain in virtually absolute alinement (the arc ofmovement 40 being of the order of 2, and the calculated movement of theslide l2 being in millionths of an inch). There is accordingly obtaineda dwell of the slide l2 which is absolute for all practical purposes,for 90 of crank-movement. The length of the connecting rod 25 issomewhat greater than the distance between the center of crank 24in itslower dead-center position and the center of the joint 22 in the alinedposition of levers 20, 2|, so as to cause the aforesaid movement of theconnected toggle-levers 20, 2| in a small arc across the position ofalinement of said levers.

The knuckle-jointed levers |4, H) are arranged in line with the line ofreciprocation of the slide l2, and the toggle-levers 20, 2| preferablyextend across the frame of an angle approximating 180 to the line ofreciprocation of the slide. By this arrangement the greatest stress islengthwise of the press-frame in a direction where the frame can bestsustain it. The force transmitted through the crank 24 is transmittedalmost wholly as a turning force to the toggle levers 20, 2 l, virtuallynone of it acting directly as a thrust against a fixed bearing orbearings. Owing to the mechanical advantage with which the toggleleversact on the knuckle-levers l4, l5, the force acting between the bearingsI! and 40 is only a small fraction of that acting between the bear ingsI1 and I8 the frame l does not have to sustain the action ofexceptionally large forces' cross-wise thereof, and the frame andtransmitting mechanism can be made exceptionally light for the forcestransmitted to the slide |2.

To obtain a relatively long stroke of the slide l2 without exceptionallylengthening the knuckle-jointed levers I4, l and the height of thepress, the toggle-lever 20 is made shorter than the lever 2|, and anelbow 42 is provided on the lever M, and the toggle-lever 20 ispivotally connected thereto; also, to the same end the knuckle-jointedlever I4 is made shorter than the lever l5.

The crankshaft 31 is preferably located at the top of the press-frame,and is so arranged that the crank 24 and connecting-rod 25 are in theirdead center position when the knucklejointed levers |4, |5 are in theirposition of alinement.

A clutch 50 of the oscillatory-key type is preferably provided betweenthe driven crankshaft 31 and the driving gear-wheel 35. A known clutchof this type and its operating mechanism is illustrated in Figs. 5, 6and '7. The clutch is constructed and arranged to disengage and engagethe driving and driven parts at positions corresponding to the top andbottom positions of the crank 24 and slide l2. The key 5| is oscillatedto engage and disengage in the notch or recess 52 by means of a collar55 having a limited amount of angular movement (against the pressure ofa spring 51) with reference to shaft 31 and associated parts in whichthe key 5| is mounted. The collar has a cam-notch 59 into which a tail60 on key 5| projects, and by means of which the key 5| is oscillated toand from engaging'position with notch 52. The collar 55 also has twoangularly spaced abutments 64, 55 adapted and arranged to be engaged byone or more latches. As here shown, two latches 66, 61 are used, and theabutments 64, 65 are off-set laterally, so that latch 66 engagesabutment 64, and 61 engages 65. To disengage the clutch latch 66 isreleased so as to lie in the path of *abutment 64. When abutment 64 isstruck, the

collar 55 is held still while the crank-shaft 31 and the parts keyedthereon continue to rotate to a limited extent, during which time thekey 5| is oscillated to disengage it from notch 52 in the driving part,and thereby bring the slide l2 to rest at the top of its stroke. Themovement of slide I2 is started again by removing latch 66 from the pathof abutment 54, whereupon collar 55 by the action of spring 51,cam-notch 59 and tail 60, oscillates key 5| to engage the notch 52 inthe driving part. Latch 6! in the path of abutmnt 65 operates todisengage the clutch at the bottom-of-the-stroke position of the slide|2.

The rotation of collar 55 is stopped while the here shown, through anangle of 25. During this angular movement of shaft 31 the key 5| isoscillated to a position to clear notch 52. The upward movement of slide2 is started by removing latch 61 from the path of abutment 65,whereupon collar 55 operates to oscillate key 5| to engage it in notch52 of the driving part. About 25 to 30 of movement of the crank-shaft 31is allowed for movement of the oscillating key 5| from its fully engagedposition with the notch 52 in the hub of the gear-wheel 35 to its fullydisengaged position, which amount of angular movement is in accordancewith usual practice, and the key 5| is so located on the shaft 37 thatits aforesaid movement of 25 to 30 occurs within the 90 of angularmovement of the crankshaft 31 through which the crank 24 travels in itsarc passing through its dead-center position and during which 90 ofangular movement the knuckle-jointed levers l4, I5 are in virtualabsolute alinement. During said 90 of angular movement of the crank 24,the force required to move the toggle-levers 20, 2| is very small ascompared with the force required to move them just before and after thelimits of said 90 arc of movement of the crank 24 are reached when theslide is being forced with a maximum effort to and from itsbottom-of-the-stroke position. Consequently, with the clutch parts soarranged that the 25or so of crank-shaft movement required for operatingthe clutch is included within the aforesaid 90 arc of movement of thecrank 24, the parts of the clutch 50 can be disengaged and re-engagedagainst a relatively small resistance while maximum force is acting onthe slide I2 and the frame I0 is stressed to its maximum. By suitablyspacing the aforesaid 25 are required for the clutch operation withinthe aforesaid 90 arc of movement of the crank 24, a suitable lag to thebeginning of the clutch operation after the crank 24 reaches thebeginning of its aforesaid 90 arc of movement may be obtained; and alsoa suitable engagement of the parts of the clutch 50 in advance of thecrank 24 reaching the end of its aforesaid 90 arc of movement may beobtained so the driving mechanism (motor, fiy-wheel 30, gear-wheel 35,and shaft 31) may drive the crank 24 through a greater or less angleagainst a relatively small resistance, and thereby gain, or retain,momentum, before the crank 24 meets the greatly increased resistance atthe end of its aforesaid 90 arc of movement. As shown in Fig. 3, theclutch 50 is so positioned that its parts are disengaged and re-engagedat about the middle of said 90 arc of movement of crank 24, so thatdisengagement begins after the crank 24 has moved about 20 in itsaforesaid 90 arc of movement, and engagement is completed about 45before the crank 24 reaches the end of its aforesaid 90 arc of movement.It becomes practicable by my invention to disengage and re-engage aclutch of the positive engagement type with the slide in itsbottom-of-the-stroke position and while held under the action thereon ofan enormous force.

The clutch operating angle need not however be geometrically includedwithin the 90 angle which passes through the dead-center position of thecrank, but may be included as a matter of timing, so that the clutchoperation takes place within the time that the crank 24 is within said90 angle or arc of movement.

Operation Starting with the clutch so engaged, and with en ages h id 2at t t p o t stroke s tio s n in Fig. 1) the crank H'drives the slide l2through the toggle-levers 20, 2| and the knucklerjointed levers Ill, IEto its bottom-ofethe stroke position, shown diagrammatically in Fig. 3.The knucklejoihted levers M, l5, reach and maintain virtually absolutealinement, andthe slide I? dwells virtually absolutely, while the crankmoves from a to b Fig. 3 through an angle of approximately (the crankmovement is in fact through a slightly greater angle) and the togglelevers move back and forth through a small angle 0 across the line ofdead-center alinement of said levers 20, 2|. The leverages of thetoggle-levers 20, 21 and of the knuckle-jointed levers l4, l5 are greatas these levers approach alinement, and the tool on the slide 12 isforced against the piece of metal in the tool on the bed of the presswith an enormous force and by reaction the press frame iscorrespondingly stressed.

A piece of metal (a strip of steel to be formed into a flangedhalf-round liner for a bearing, for example) is forced into shape by thetools on the slide and bed during the approach of the slide to the bed,and the formed piece of metal is held between the immovable press-toolsunder enormous pressure for a time corresponding to the movement of thecrank 24 from a to b through an angle of 90, during which time themolecules of, the metal have time to readjust themselves so that theformed piece of metal retains the shape to which it is forced by thepress-tools to a very much greater degree than in presses Where thedwell of the slide is not virtually absolute. In metal-pieces formed inordinary presses, the molecular forces in the metal are such as to causeparts of the formed piece, when released by the press tools, to departtwo or three thousandths of an inch from their position in the die. Bymy press the variation of the formed piece from the shape to which it isforced within the tools of the press, may be reduced to the order oftenths of thousandths of an inch.

By disengaging the clutch 5|] while the crank 2 3 is in its 90 angle a-bof movement, (which may be readily and practicably done owing to themechanical principles embodied in my invention) the time during whichthe slide l2 may be held immovable by the knuckle-jointed levers :4, I5may be increased to any desired extent. By disengaging the clutch 50 forabout 3 seconds, metal strips (cold steel for example) can be given ashape which varies only two or three ten-thousandths of an inch from itsshape within the press-tools.

The knuckle-jointed levers l4, l5, when alined, transmit virtually allof the stress to the pressframe. The levers I4, l5 remain in theiralined position through the angle zt-b (approximately 90) of movement ofcrank 24, and while so alined, only a relative small force is requiredto turn the crank, and to oscillate the toggle-levers 2!), 2|. Theclutch 50 may be operated within the time in which the crank 24 is insaid 90 arc of its movement against a minimum of resistance, and bytiming the engagement of the clutch parts so that it occurs while thecrank 24 is well within said 90 angle 0-1), the driving parts (motor,flywheel 33, gear wheel 35 etc.) may gain or retain momentum before thecrank 24 reaches the end (b) of the said 90 angle and the greatresistance to moving the knuckle-jointed levers l4, l5 and lifting theslide 12 to separate the press-tools, is encountered. The strain on theclutch parts during engagement and disengagement is relatively small,the operation is easy, and excessive wear and frequent breakageeliminated.

The invention may receive other embodiments than that hereinspecifically illustrated and described.

What is claimed is:

1. A press comprising a reciprocatory slide, and means for actuating thesame, comprising a pair of knuckle-jointed levers, a pair of jointedtoggle levers connected to said knuckle-jointed levers, a crank, and aconnection between said crank and toggle levers, said connection havinga length somewhat greater than the distance between the center of thecrank in its lower dead center position and the center of the joint ofsaid toggle levers in the alined position of said togglelevers, so thatthe toggle-levers move in a small arc across the line of dead-centeralinement of said toggle-levers through a wide angle of movement of thecrank, and while said knuckle-jointed levers are in virtually absolutealinement.

2. A press according to claim 1, wherein the toggle-lever proximate theconnection to the knuckle-jointed levers is substantially shorter thanthe other toggle lever.

3. A press according to claim 1, wherein one of said knuckle-jointedlevers has an elbow thereon, and wherein the toggle-lever proximate theconnection to the knuckle-jointed levers is substantially shorter thanthe other toggle-lever and connected to said elbow.

4. A press according to claim 1, wherein said toggle levers are soarranged as to be in substantial alinement along a line approximating atto the alined position of the knuckle-jointed levers, ahd wherein saidcrank and connecting rod are so arranged as to be alined, in adead-center position parallel to the alined position of saidknuckle-jointed levers.

5. A press according to claim 1, further comprising a clutch of thepositive engagement type, and positioned with relation to said crank sothat the angular movement required for disengagement and reengagement ofits parts is included within the aforesaid wide angle of movement ofsaid crank.

6. A press comprising a reciprocatory slide, and means for actuating thesame, comprising a pair of knuckle-jointed levers, a pair of jointedtoggle levers connected to said knuckle-jointed levers, a crank, and aconnection between said crank and toggle levers, said connection havinga length somewhat greater than the distance between the center of thecrank in its lower dead center position and the center of the joint ofsaid toggle levers in the alined position of said toggle levers, so thatthe toggle-levers move in a small arc across the line of dead-centeralinement of said toggle-levers through an angle of movement of thecrank of approximately 90.

7. A press according to claim 6, further comprising a clutch of thepositive engagement type the parts of which are movable to disengagingand re-engaging position in about 25 of angular movement of said crank,and positioned with relation to said crank so that the 25 of movement orthereabout required for its operation are included within the aforesaid90 of movement of said crank.

8. A press comprising a reciprocatory slide, and means for actuating itcomprising a crank, means for driving said crank, a clutch of thepositive engagement type the parts of which are movable to disengagingand l e-engaging position within a given angular movement of said crank,and means driven by said crank for holding said slide in itsbottom-of-the-stroke position through a greater angle of movement ofsaid crank than the aforesaid angular movement for operating saidclutch.

9. A press comprising a reciprocatory slide, and means for actuating itcomprising acrank, means for driving said crank, a clutch of thepositive engagement type the parts of which are movable to disengagingand re-engaging position within about 25 of angular movement of saidcrank, and means driven by said crank for holding said slide in itsbottom-of-the-stroke position through approximately a 90 angle ofmovement of said crank, said 25 angle being included within said 90angle.

WILLIAM KLOCKE.

